Conventional intercom systems used in television studios comprise a number of mobile units connected via cables to a remote base station which coordinates audio signals to and from the mobile units. This sort of system can be inconvenient to use as a result of the constraint placed by the cables on the movements of the users of the mobile units.
Such constraints are generally not present (or are less of a problem) in a wireless intercom system, but in this case, it is only possible for communications from a given unit to be either broadcast to all mobile units simultaneously or to a selected one of the mobile units.